Method for inducing seed development by down-regulating expression of the FIS2 gene

Abstract

The present invention provides a method of inducing seed development in plants, preferably in the absence of sexual fertilisation, said method comprising inhibiting or preventing the expression of one or more regulatory polypeptides that otherwise prevent asexual seed development in plants. The invention further provides novel genetic sequences. The invention further provides transformed plants having a wide range of novel phenotypes including, but not limited to, the ability to reproroduce asexually, develop seed in the absence of fertilisation, and the ability to produce parthenocarpic fruit or seedless fruit or fruits with soft seed traces such that the fruit are marketable as less seedy than wild-type fruit or seedless. The isolated nucleic acid molecules are further useful in the detectrion of proteins and genetic sequences which interact with the polypeptides encoded by said nucleic acid molecules in the regulation of seed development in plants.

We claim:  
     
         1 . A method of inducing the development of seed in a plant, comprising introducing into said plant or a parent of said plant, genetic material which reduces expression of a gene in one or more female reproductive cells of said plant, wherein said gene hybridizes to SEQ ID NO:6 or a complementary form thereof under stringent conditions, wherein the reduction of expression of the gene is sufficient to induce development of seed in the plant.  
     
     
         2 . The method of  claim 1 , wherein the gene encodes a polypeptide comprising the amino acid sequence motif C-X 2 -C-X n -H-X 4 -H, wherein n=10 to 15 amino acid residues in length and wherein numerical values indicate the number of consecutive multiple occurrences of a particular amino acid residue.  
     
     
         3 . The method of  claim 1 , wherein the gene encodes a polypeptide which comprises SEQ ID NO:2.  
     
     
         4 . The method of  claim 1 , wherein the expression of the gene is reduced by a method comprising mutagenesis of the gene.  
     
     
         5 . The method of  claim 4  wherein the mutagenesis produces a null allele of the gene.  
     
     
         6 . The method of  claim 4  wherein the mutagenesis is performed using a chemical mutagen.  
     
     
         7 . The method of  claim 6  wherein the chemical mutagen is EMS.  
     
     
         8 . The method of  claim 4 , wherein the mutagenesis comprises insertion of a nucleic acid molecule into the gene.  
     
     
         9 . The method of  claim 8 , wherein the nucleic acid molecule comprises a member selected from the group consisting of T-DNA, a gene targeting molecule and a transposon.  
     
     
         10 . The method of  claim 1 , wherein the seed comprises an endosperm.  
     
     
         11 . The method of  claim 1 , wherein the seed lacks a functional embryo structure.  
     
     
         12 . The method of  claim 11 , wherein the seed is a soft seed.  
     
     
         13 . The method of  claim 1 , wherein the seed is able to germinate.  
     
     
         14 . The method of  claim 1 , wherein the seed is autonomously produced.  
     
     
         15 . The method of  claim 14 , wherein the seed is produced independent of fertilization.  
     
     
         16 . A method of producing seedless or soft-seeded fruit in a plant, comprising introducing into said plant or a parent of said plant genetic material which reduces expression of a gene in one or more female reproductive cells of said plant, wherein said gene hybridizes to SEQ ID NO:6 or a complementary form thereof under stringent conditions and wherein the reduction of expression of the gene is sufficient to produce seedless or soft-seeded fruit in the plant.  
     
     
         17 . The method of  claim 1 , wherein the gene comprises the nucleotide sequence set forth in SEQ ID NO:6 or SEQ ID NO:7.  
     
     
         18 . The method of  claim 16 , wherein the gene comprises the nucleotide sequence set forth in SEQ ID NO:6 or SEQ ID NO:7.  
     
     
         19 . The method of  claim 1 , wherein the plant is a transgenic plant.  
     
     
         20 . The method of  claim 1 , wherein the genetic material encodes an antisense, a ribozyme, sense or gene silencing RNA.  
     
     
         21 . The method of  claim 16 , wherein the genetic material encodes an antisense, a ribozyme, sense or gene silencing RNA.  
     
     
         22 . The method of  claim 16 , wherein the expression of said gene is reduced by a method comprising mutagenesis of the gene.  
     
     
         23 . The method of  claim 22 , wherein the mutagenesis comprises the insertion of a nucleic acid molecule into the gene.  
     
     
         24 . The method of  claim 23 , wherein the nucleic acid molecule comprises a member selected from the group consisting of T-DNA, a gene targeting molecule and a transposon.  
     
     
         25 . A plant generated by the process of introducing genetic material to a cell of a plant, which genetic material reduces expression of a gene which hybridizes to SEQ ID NO:6 or a complementary form thereof under stringent conditions and then regenerating a plant from said plant cell.  
     
     
         26 . The plant of  claim 25 , comprising a nucleic acid molecule inserted into said gene.  
     
     
         27 . A progeny or seeds of the plant of  claim 25 , wherein the progeny or seeds comprise the genetic material.  
     
     
         28 . A progeny or seeds of the plant of  claim 26 , wherein the progeny or seeds comprise the nucleic acid molecule inserted into said gene.  
     
     
         29 . A plant comprising seed developed by the method of  claim 1 .  
     
     
         30 . A progeny plant or seeds obtained from the plant of  claim 29 , wherein said progeny plant or seeds comprise the genetic material.  
     
     
         31 . A seedless or soft-seeded fruit produced by the method of  claim 23 , wherein the seedless or soft-seeded fruit comprises the nucleic acid molecule inserted into the gene.  
     
     
         32 . A seedless or soft-seeded fruit produced by the method of  claim 16 , wherein the seedless or soft-seeded fruit comprises the genetic material.  
     
     
         33 . The method of  claim 20 , wherein the genetic material encodes an antisense RNA.  
     
     
         34 . The method of  claim 20 , wherein the genetic material encodes a ribozyme.  
     
     
         35 . The method of  claim 20 , wherein the genetic material encodes sense RNA.  
     
     
         36 . The method of  claim 20 , wherein the genetic material encodes gene silencing RNA.  
     
     
         37 . The plant of  claim 25  wherein the genetic material encodes an antisense, a ribozyme, sense or gene silencing RNA.  
     
     
         38 . The plant of  claim 37 , wherein the genetic material encodes an antisense RNA.  
     
     
         39 . The plant of  claim 37 , wherein the genetic material encodes a ribozyme.  
     
     
         40 . The plant of  claim 37 , wherein the genetic material encodes sense RNA.  
     
     
         41 . The plant of  claim 37 , wherein the genetic material encodes gene silencing RNA.